US4194073A - Olefin polymerization - Google Patents

Olefin polymerization Download PDF

Info

Publication number
US4194073A
US4194073A US05/866,900 US86690078A US4194073A US 4194073 A US4194073 A US 4194073A US 86690078 A US86690078 A US 86690078A US 4194073 A US4194073 A US 4194073A
Authority
US
United States
Prior art keywords
polymerization
aromatic compound
process according
catalyst
reactor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US05/866,900
Inventor
Max P. McDaniel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Phillips Petroleum Co
Original Assignee
Phillips Petroleum Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Phillips Petroleum Co filed Critical Phillips Petroleum Co
Priority to US05/866,900 priority Critical patent/US4194073A/en
Application granted granted Critical
Publication of US4194073A publication Critical patent/US4194073A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F10/00—Homopolymers and copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S526/00—Synthetic resins or natural rubbers -- part of the class 520 series
    • Y10S526/903—Monomer polymerized in presence of transition metal containing catalyst and hydrocarbon additive affecting polymer properties of catalyst activity

Definitions

  • This invention relates to the polymerization of olefins.
  • this invention relates to the polymerization of 1-olefins in the presence of a chromium oxide catalyst and an adjuvant.
  • this invention relates to a method of polymerizing 1-olefins in the presence of a catalyst such as chromium oxide and an aromatic compound such as benzene, o-xylene, monohalogenated derivatives of benzene and o-xylene and mixtures thereof.
  • this invention relates to the polymerization of 1-olefins in the presence of a supported chromium oxide catalyst that has been pretreated with an aromatic compound such as benzene, o-xylene, a monohalogenated derivative of benzene or o-xylene or mixtures thereof.
  • melt index is an important characteristic in a polymer. Since melt index is indicative of molecular weight and thus is further a measure of flow of the polymer, the higher the melt index of the polymer the better the polymer will perform for purposes where complete polymer flow to fill a mold, or the like, is required for the formation of an article prior to experiencing any setting of the polymer. A method to obtain polymers having a high melt index, therefore, is of significant value to the art.
  • an adjuvant which consists essentially of at least one aromatic compound selected from among benzene, o-xylene, and monohalogenated derivatives thereof, results in the production of a polymer having a higher melt index relative to polymers made under similar conditions in the absence of the adjuvant.
  • Another object of the present invention is to provide a method for producing polymers and copolymers of 1-olefins having an increased melt index.
  • This invention concerns the production of normally solid 1-olefin homopolymers or copolymers thereof with a supported chromium oxide catalyst and an aromatic compound as an adjuvant for the catalyst.
  • the polymers are made by contacting the appropriate monomers with the catalyst and adjuvant under polymerization conditions.
  • aromatic compounds contemplated in practicing the invention are selected from among benzene, o-xylene, the monohalogenated derivatives of benzene and o-xylene and mixtures thereof.
  • Benzene is the presently preferred compound.
  • the adjuvant can be added as a separate stream to the reactor before, during or after the charging of the diluent.
  • the catalyst can be pretreated with the adjuvant prior to charging the catalyst to the reactor.
  • a combination of the two embodiments is also contemplated within the scope of this invention, i.e. charging adjuvant to the reactor as a separate stream as well as pretreating the catalyst to be used.
  • a supported chromium oxide catalyst and an aromatic compound as an adjuvant for the catalyst are contacted with 1-olefins under polymerization conditions to produce normally solid 1-olefin homopolymers or 1-olefin copolymers.
  • Appropriate polymerization conditions are any of the well-known polymerization processes in the art utilizing a chromium oxide catalyst.
  • the preferred polymerization conditions of the present invention are those of a particle form polymerization process. Such conditions are disclosed in U.S. Pat. No. 3,950,316.
  • the melt index of the polymers produced according to this invention are increased relative to polymers made under similar conditions in the absence of the adjuvant and such differences are more clearly observed in the particle form process.
  • aromatic compounds contemplated in practicing the instant invention are selected from among benzene, o-xylene, the monohalogenated derivatives of benzene and o-xylene and mixtures thereof.
  • exemplary compounds include fluorobenzene, chlorobenzene, bromobenzene, 1,2-dimethyl-4-chlorobenzene and the like.
  • Benzene is the presently preferred compound.
  • the supported chromium oxide catalyst used in the process of the instant invention can utilize any of the various commercially available heat resistant oxides, such as silica, alumina or silica-alumina, as a catalyst support. Chromium oxide catalyst such as those consisting of chromium oxide, silica and titanium are also appropriate.
  • the chromium oxide component of the catalyst system is placed on the catalyst support by any of the several conventional methods, such as impregnation, distillation, sublimation, or the like, followed by calcination.
  • Suitable chromium compounds which may be used include chromium oxides, halides, oxyhalides, phosphate, sulfate, oxalate, nitrates, acetates, alcoholates or other organochromium compounds convertible to chromium oxide by calcination.
  • the chromium compound is supported on the heat resistant oxide support and the supported chromium compound is calcined to activate the catalyst component.
  • the calcination process for activation of the catalyst component is conducted by heating in a stream of gas, it is preferred that the gas contain oxygen and be substantially water-free. Inert gases, however, such as carbon dioxide and nitrogen, can be used. Suitable calcination temperatures usually range from 450° to 2,200° F., preferably 750° to 2,000° F. and the calcination time usually ranges from anywhere between several minutes to 30 or 40 hours, preferably in the range of 30 minutes to 10 hours.
  • the polymerization to which the present invention is applicable is the polymerization of at least one polymerizable 1-olefin, preferably normally solid homopolymers of ethylene or copolymers of ethylene, with another 1-olefin containing 3-8 carbon atoms per molecule.
  • the olefin polymer can be produced from at least one aliphatic mono-1-olefin having 2-8 carbon atoms per molecule.
  • Exemplary copolymers include those of ethylene/propylene, ethylene/1-butene, ethylene/1-hexene, ethylene/1-octene and the like. The major portion of said copolymers is derived from ethylene. These polymers are well suited for extrusion, blow molding, injection molding, and the like.
  • Suitable diluents for the polymerization medium include hydrocarbons having 3 to 12 carbon atoms per molecule such as paraffins, cycloparaffins, and aromatics with the paraffinic hydrocarbons being more preferred.
  • Exemplary diluents include n-butane, isobutane, n-pentane, isopentane, n-hexane, 2,2,4-trimethylpentane, cyclopentane, cyclohexane, methylcyclohexane, n-dodecane and mixtures thereof.
  • the amount of diluent used depends upon the particular polymerization process used, the details of which are generally well-known in the art. For example, in a particle form process, the diluent is generally present in a sufficient amount to ensure that the 1-olefin monomer concentration is of the order of 2-10 weight percent although concentrations outside this range can be employed if desired.
  • the adjuvant can be added as a separate stream to the reactor before, during or after the charging of the diluent to the reactor.
  • the amount of adjuvant charged to the reactor can vary from about 1 to about 800 ppm, more preferrably from about 1 to about 500 ppm, based on the weight of diluent contained in the reactor.
  • the catalyst can be pretreated with the adjuvant of the instant invention prior to charging the catalyst to the reactor.
  • pretreating the catalyst with the adjuvant the catalyst is first activated normally in a fluidized bed with dry air and reduced by a suitable reducing agent such as carbon monoxide or the like. While excluding air, the reduced catalyst is then contacted with vapors of the adjuvant sufficient to add at least 1 mole of the adjuvant per mole of chromium present in the catalyst to produce the modified catalyst. After the treatment, the catalyst is ready to be charged to the reactor.
  • Adjuvant in excess of 1 mole per mole of chromium does not bond with the chromium, but can be utilized as though added in a separate stream to the reactor as disclosed in embodiment 1.
  • a combination of the two embodiments, that of pretreating the catalyst with the adjuvant and also adding the adjuvant as a separate stream to the reactor, is contemplated within the scope of the present invention.
  • the amount of melt index increase expected can range from about 5 to about 25% as calculated from the actually determined values of the polymers made.
  • a series of runs was made in a particle form polymerization process by contact of ethylene with a supported chromium oxide catalyst (cogel) containing 2.5 wt.% Ti, 1 wt.% Cr and the balance silica based on the dry components.
  • the catalyst was activated by heating it at 1600° F. (871° C.) in dry air for 4 hours. Portions of the catalyst (0.03-0.07 g range) were individually charged to the stirred reactor. Adjuvant was added, isobutane (570 g) was charged and the reactor and contents were heated to 230° F. (110° C.), sufficient ethylene was admitted to reach a pressure of 550 psig (3.8 MPa gage) and the run was started.
  • cogel supported chromium oxide catalyst
  • Ethylene was added on demand as required during the run to maintain the pressure at 550 psig. Each run was of sufficient duration to obtain about 5000 g polymer per g catalyst. Melt index values are corrected to a productivity level of 5000 g polymer per g catalyst to accurately compare results. The adjuvant and quantity thereof charged to the reactor and results obtained are given in Table 1. The percent increase or decrease in melt index shown is based solely on the actual melt index values determined for each run. The calculated melt index ranges are based on the estimated reproducibilities at a given melt index shown in FIG. 1.
  • Portions of the catalyst used in the first example were activated by heating them in dry air for 4 hours at 1600° F. While the temperature was being reduced to about 600°-700° F. (315°-371° C.) the air was flushed out with dry nitrogen replaced with dry CO while maintaining the temperature in the 600°-700° F. range for about 1 hour to reduce the chromium to a coordinately unsaturated state. The carbon monoxide was then flushed out with dry nitrogen while maintaining the temperature at 600°-700° F. and the temperature was reduced to about 25° C. in the presence of nitrogen. Each reduced catalyst portion was then contacted with sufficient adjuvant vapor to add one mole thereof per mole of chromium present in the catalyst.
  • the treated catalyst was charged to the reactor without further treatment along with isobutane diluent and ethylene. Polymerization was conducted at 230° F. and 550 psig in the presence of about 570 g isobutane diluent and 0.05- 0.07 g catalyst.
  • the adjuvants employed and results obtained are given in Table 2. The calculated melt index ranges and % increase in melt index shown are given on the same basis as in the first example.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Transition And Organic Metals Composition Catalysts For Addition Polymerization (AREA)

Abstract

Higher melt index 1-olefin polymers are produced by polymerizing the monomers in contact with a supported chromium oxide catalyst and an aromatic compound, e.g. benzene. The aromatic compound can be added as a separate stream to the reactor before, during or after charging the diluent to the reactor or the catalyst can be pretreated with the aromatic compound prior to charging the catalyst to the reactor.

Description

BACKGROUND OF THE INVENTION
This invention relates to the polymerization of olefins. In another aspect, this invention relates to the polymerization of 1-olefins in the presence of a chromium oxide catalyst and an adjuvant. In another aspect, this invention relates to a method of polymerizing 1-olefins in the presence of a catalyst such as chromium oxide and an aromatic compound such as benzene, o-xylene, monohalogenated derivatives of benzene and o-xylene and mixtures thereof. In yet another aspect, this invention relates to the polymerization of 1-olefins in the presence of a supported chromium oxide catalyst that has been pretreated with an aromatic compound such as benzene, o-xylene, a monohalogenated derivative of benzene or o-xylene or mixtures thereof.
High melt index is an important characteristic in a polymer. Since melt index is indicative of molecular weight and thus is further a measure of flow of the polymer, the higher the melt index of the polymer the better the polymer will perform for purposes where complete polymer flow to fill a mold, or the like, is required for the formation of an article prior to experiencing any setting of the polymer. A method to obtain polymers having a high melt index, therefore, is of significant value to the art.
It has now been discovered in accordance with this invention that the use of an adjuvant, which consists essentially of at least one aromatic compound selected from among benzene, o-xylene, and monohalogenated derivatives thereof, results in the production of a polymer having a higher melt index relative to polymers made under similar conditions in the absence of the adjuvant.
It is an object of the present invention, therefore, to provide an improved method for producing polymers and copolymers of 1-olefins.
Another object of the present invention is to provide a method for producing polymers and copolymers of 1-olefins having an increased melt index.
Other aspects, objects, and the several advantages of this invention will be apparent from the disclosure and the appended claims.
SUMMARY OF THE INVENTION
This invention concerns the production of normally solid 1-olefin homopolymers or copolymers thereof with a supported chromium oxide catalyst and an aromatic compound as an adjuvant for the catalyst. The polymers are made by contacting the appropriate monomers with the catalyst and adjuvant under polymerization conditions.
The aromatic compounds contemplated in practicing the invention are selected from among benzene, o-xylene, the monohalogenated derivatives of benzene and o-xylene and mixtures thereof. Benzene is the presently preferred compound.
In one embodiment, the adjuvant can be added as a separate stream to the reactor before, during or after the charging of the diluent. In a second embodiment, the catalyst can be pretreated with the adjuvant prior to charging the catalyst to the reactor. A combination of the two embodiments is also contemplated within the scope of this invention, i.e. charging adjuvant to the reactor as a separate stream as well as pretreating the catalyst to be used.
DETAILED DESCRIPTION OF THE INVENTION
In the process of this invention, a supported chromium oxide catalyst and an aromatic compound as an adjuvant for the catalyst are contacted with 1-olefins under polymerization conditions to produce normally solid 1-olefin homopolymers or 1-olefin copolymers. Appropriate polymerization conditions are any of the well-known polymerization processes in the art utilizing a chromium oxide catalyst. The preferred polymerization conditions of the present invention are those of a particle form polymerization process. Such conditions are disclosed in U.S. Pat. No. 3,950,316. The melt index of the polymers produced according to this invention are increased relative to polymers made under similar conditions in the absence of the adjuvant and such differences are more clearly observed in the particle form process.
The aromatic compounds contemplated in practicing the instant invention are selected from among benzene, o-xylene, the monohalogenated derivatives of benzene and o-xylene and mixtures thereof. Exemplary compounds include fluorobenzene, chlorobenzene, bromobenzene, 1,2-dimethyl-4-chlorobenzene and the like. Benzene is the presently preferred compound.
The supported chromium oxide catalyst used in the process of the instant invention can utilize any of the various commercially available heat resistant oxides, such as silica, alumina or silica-alumina, as a catalyst support. Chromium oxide catalyst such as those consisting of chromium oxide, silica and titanium are also appropriate. The chromium oxide component of the catalyst system is placed on the catalyst support by any of the several conventional methods, such as impregnation, distillation, sublimation, or the like, followed by calcination. Suitable chromium compounds which may be used include chromium oxides, halides, oxyhalides, phosphate, sulfate, oxalate, nitrates, acetates, alcoholates or other organochromium compounds convertible to chromium oxide by calcination. The chromium compound is supported on the heat resistant oxide support and the supported chromium compound is calcined to activate the catalyst component.
The calcination process for activation of the catalyst component is conducted by heating in a stream of gas, it is preferred that the gas contain oxygen and be substantially water-free. Inert gases, however, such as carbon dioxide and nitrogen, can be used. Suitable calcination temperatures usually range from 450° to 2,200° F., preferably 750° to 2,000° F. and the calcination time usually ranges from anywhere between several minutes to 30 or 40 hours, preferably in the range of 30 minutes to 10 hours.
The polymerization to which the present invention is applicable is the polymerization of at least one polymerizable 1-olefin, preferably normally solid homopolymers of ethylene or copolymers of ethylene, with another 1-olefin containing 3-8 carbon atoms per molecule. As an example, the olefin polymer can be produced from at least one aliphatic mono-1-olefin having 2-8 carbon atoms per molecule. Exemplary copolymers include those of ethylene/propylene, ethylene/1-butene, ethylene/1-hexene, ethylene/1-octene and the like. The major portion of said copolymers is derived from ethylene. These polymers are well suited for extrusion, blow molding, injection molding, and the like.
Suitable diluents for the polymerization medium include hydrocarbons having 3 to 12 carbon atoms per molecule such as paraffins, cycloparaffins, and aromatics with the paraffinic hydrocarbons being more preferred. Exemplary diluents include n-butane, isobutane, n-pentane, isopentane, n-hexane, 2,2,4-trimethylpentane, cyclopentane, cyclohexane, methylcyclohexane, n-dodecane and mixtures thereof.
The amount of diluent used depends upon the particular polymerization process used, the details of which are generally well-known in the art. For example, in a particle form process, the diluent is generally present in a sufficient amount to ensure that the 1-olefin monomer concentration is of the order of 2-10 weight percent although concentrations outside this range can be employed if desired.
In one embodiment of the present invention, the adjuvant can be added as a separate stream to the reactor before, during or after the charging of the diluent to the reactor. The amount of adjuvant charged to the reactor can vary from about 1 to about 800 ppm, more preferrably from about 1 to about 500 ppm, based on the weight of diluent contained in the reactor.
In a second embodiment, the catalyst can be pretreated with the adjuvant of the instant invention prior to charging the catalyst to the reactor. In pretreating the catalyst with the adjuvant, the catalyst is first activated normally in a fluidized bed with dry air and reduced by a suitable reducing agent such as carbon monoxide or the like. While excluding air, the reduced catalyst is then contacted with vapors of the adjuvant sufficient to add at least 1 mole of the adjuvant per mole of chromium present in the catalyst to produce the modified catalyst. After the treatment, the catalyst is ready to be charged to the reactor.
Adjuvant in excess of 1 mole per mole of chromium does not bond with the chromium, but can be utilized as though added in a separate stream to the reactor as disclosed in embodiment 1. A combination of the two embodiments, that of pretreating the catalyst with the adjuvant and also adding the adjuvant as a separate stream to the reactor, is contemplated within the scope of the present invention.
The 1-olefin polymers made in the presence of the adjuvants, particularly in a particle form polymerization process, exhibits an increase in melt index as determined by ASTM D 1238-73 at 190° C. and a load of 2160 grams compared to polymers made under the same conditions but in the absence of the adjuvants. The amount of melt index increase expected can range from about 5 to about 25% as calculated from the actually determined values of the polymers made.
The following examples are set forth as illustrative of the process of this invention and are not meant to be restrictive.
The data obtained in the following examples were analyzed with respect to the experimental error for the melt index values using FIG. 1. In the ASTM test, reproducibility at a melt index of 0.25 is ±0.04 and at a melt index of 7.0 is ±0.34. However, a variation of ±0.25 is being used for 6-7 M.I. polymers in view of a study made by the inventor. Assuming linearity between the M.I. values, the amount of experimental error for melt index values between them can be estimated from a curve based on the points. FIG. 1 represents such a curve and is, therefore, being used.
EXAMPLE 1
A series of runs was made in a particle form polymerization process by contact of ethylene with a supported chromium oxide catalyst (cogel) containing 2.5 wt.% Ti, 1 wt.% Cr and the balance silica based on the dry components. The catalyst was activated by heating it at 1600° F. (871° C.) in dry air for 4 hours. Portions of the catalyst (0.03-0.07 g range) were individually charged to the stirred reactor. Adjuvant was added, isobutane (570 g) was charged and the reactor and contents were heated to 230° F. (110° C.), sufficient ethylene was admitted to reach a pressure of 550 psig (3.8 MPa gage) and the run was started. Ethylene was added on demand as required during the run to maintain the pressure at 550 psig. Each run was of sufficient duration to obtain about 5000 g polymer per g catalyst. Melt index values are corrected to a productivity level of 5000 g polymer per g catalyst to accurately compare results. The adjuvant and quantity thereof charged to the reactor and results obtained are given in Table 1. The percent increase or decrease in melt index shown is based solely on the actual melt index values determined for each run. The calculated melt index ranges are based on the estimated reproducibilities at a given melt index shown in FIG. 1.
The results presented in Table 1 show that benzene and fluorobenzene are effective as reactor adjuvants in promoting an increase in polymer melt index during polymerization of ethylene even when taking into account the experimental variation possible in melt index determinations. The data show that toluene, p-xylene and p-dibromobenzene are of little or no value as reaction adjuvants under the conditions employed. The reason for the spurious results shown in run 3 in which a suitable quantity of benzene was used is not known. Run 1 demonstrates that 1565 ppm benzene tends to depress polymer melt index and catalyst activity based on polymer melt index and polymerization time required. This effect is noted at 313 ppm with p-xylene in run 8. The borderline results with 783 ppm benzene in run 2 are used as the basis for establishing 500 ppm as a probably reasonable upper limit for the reactor adjuvants.
                                  Table 1                                 
__________________________________________________________________________
Ethylene Polymerization with Aromatic Reaction Adjuvant                   
                                       Melt Polymerization                
                Melt Index Values      Index                              
                                            Time, minutes                 
Run                                                                       
   Reactor Adjuvant                                                       
                With  Calculated                                          
                            Without                                       
                                 Calculated                               
                                       Increase                           
                                            With Without                  
No.                                                                       
   Description                                                            
             PPM                                                          
                Adjuvant                                                  
                      Range Adjuvant                                      
                                 Range %    Adjuvant                      
                                                 Adjuvant                 
                                                      Remarks             
__________________________________________________________________________
1  benzene.sup.(a)                                                        
             1565                                                         
                4.48  4.31-4.65                                           
                            4.86 4.68-5.04                                
                                       -7.8 70   44   Comparison          
2  benzene.sup.(a)                                                        
             783                                                          
                5.16  4.97-5.35                                           
                            4.86 4.68-5.04                                
                                       6.2  57   44   Comparison          
3  benzene.sup.(a)                                                        
             313                                                          
                5.93  5.71-6.15                                           
                            5.55 5.35-5.75                                
                                       6.8  53   45   Anomalous result    
4  benzene.sup.(a)                                                        
             313                                                          
                6.44  6.21-6.67                                           
                            5.66 5.46-5.86                                
                                       14.  49   65   Invention           
5  benzene.sup.(a)                                                        
             313                                                          
                6.62  6.38-6.86                                           
                            5.70 5.49-5.91                                
                                       16.  52   45   Invention           
6  benzene.sup.(a)                                                        
             313                                                          
                6.51  6.28-6.74                                           
                            5.67 5.47-5.87                                
                                       15.  57   47   Invention           
7  toluene   313                                                          
                5.33  5.13-5.53                                           
                            5.22 5.03-5.41                                
                                       2.1  55   45   Comparison          
8  p-xylene  313                                                          
                2.24  2.14-2.34                                           
                            5.21 5.01-5.41                                
                                       -57. 130  70   Comparison          
9  fluorobenzene                                                          
             300                                                          
                6.07  5.85-6.29                                           
                            5.52 5.32-5.72                                
                                       10.  41   42   Invention           
10 p-dibromobenzene                                                       
             2  5.62  5.42-5.82                                           
                            5.45 5.35-5.65                                
                                       3.1  45   46   Comparison          
__________________________________________________________________________
 .sup.(a) Thiophene free.
EXAMPLE 2
Portions of the catalyst used in the first example were activated by heating them in dry air for 4 hours at 1600° F. While the temperature was being reduced to about 600°-700° F. (315°-371° C.) the air was flushed out with dry nitrogen replaced with dry CO while maintaining the temperature in the 600°-700° F. range for about 1 hour to reduce the chromium to a coordinately unsaturated state. The carbon monoxide was then flushed out with dry nitrogen while maintaining the temperature at 600°-700° F. and the temperature was reduced to about 25° C. in the presence of nitrogen. Each reduced catalyst portion was then contacted with sufficient adjuvant vapor to add one mole thereof per mole of chromium present in the catalyst. The treated catalyst was charged to the reactor without further treatment along with isobutane diluent and ethylene. Polymerization was conducted at 230° F. and 550 psig in the presence of about 570 g isobutane diluent and 0.05- 0.07 g catalyst. The adjuvants employed and results obtained are given in Table 2. The calculated melt index ranges and % increase in melt index shown are given on the same basis as in the first example.
The data presented in Table 2 show that reduced supported chromium oxide catalysts contacted with either benzene, o-xylene or fluorobenzene prior to being used in polymerizing ethylene have their melt index capability improved by the treatment. The results show that iodobenzene and perfluorobenzene, on the other hand, have little or no effect on improving catalyst melt index capability under the conditions employed.
                                  Table 2                                 
__________________________________________________________________________
Ethylene Polymerization with Treted Catalyst                              
                                              Melt                        
Catalyst              Melt Index Values       Index Polymerization        
Run                                                                       
   Weight                                                                 
        Treated Catalyst    Calculated  Calculated                        
                                              Increase                    
                                                    Time, minutes         
No.                                                                       
   g    Adjuvant  Color                                                   
                      Treated                                             
                            Range Untreated                               
                                        Range %     Treated               
                                                         Untreated        
__________________________________________________________________________
1  0.0558                                                                 
        benzene   green                                                   
                      3.82  3.67-3.97                                     
                                  2.92  2.80-3.04                         
                                              24.   84   93               
2  0.0599                                                                 
        benzene   green                                                   
                      4.10  3.94-4.26                                     
                                  3.40  3.26-3.54                         
                                              17.   72   75               
3  0.0527                                                                 
        o-xylene  green                                                   
                      3.71  3.56-3.86                                     
                                  3.26  3.13-3.39                         
                                              8.0   85   81               
4  0.0665                                                                 
        fluorobenzene                                                     
                  green                                                   
                      3.38  3.24-3.52                                     
                                  3.26  3.13-3.39                         
                                              3.7   95   81               
5  0.0648                                                                 
        perfluorobenzene                                                  
                  green                                                   
                      3.04  2.91-3.17                                     
                                  3.40  3.26-3.54                         
                                              -11.  94   75               
6  0.0518                                                                 
        iodobenzene                                                       
                  brown                                                   
                      3.15  3.02-3.28                                     
                                  3.26  3.13-3.39                         
                                              -3.4  80   81               
__________________________________________________________________________
Certain modifications of the invention will become apparant to those skilled in the art and the illustrative details enclosed are not to be construed as imposing unnecessary limitations on the invention.

Claims (18)

We claim:
1. A process for the polymerization of 1-olefins in the presence of a chromium oxide catalyst and a liquid diluent which comprises adding to the reactor either before, during or after the charging of the diluent to the reactor an effective melt index increasing amount of fluorobenzene under such conditions that a polymer is produced having an increased melt index relative to polymers made under similar conditions in the absence of the fluorobenzene.
2. A polymerization process for the polymerization of 1-olefins in the presence of a chromium oxide catalyst and a liquid diluent which comprises the steps of:
(a) reducing said chromium oxide catalyst with a suitable reducing agent,
(b) contacting said reduced catalyst with vapors of at least one aromatic compound selected from the group consisting essentially of: benzene, o-xylene, the fluorine, chlorine, and bromine monohalogenated derivatives of benzene and o-xylene and mixtures thereof, under such conditions as to add at least one mole of said aromatic compound per mole of chromium present in the catalyst,
(c) charging said pretreated chromium oxide catalyst to the reactor and then polymerizing said 1-olefin, and
(d) adding to the reactor either before, during or after the charging of the diluent to the reactor additional aromatic compound.
3. A process according to claim 2 wherein said suitable reducing agent of step (a) is carbon monoxide.
4. A process according to claim 2 wherein said aromatic compound is benzene.
5. A process according to claim 2 wherein said aromatic compound is o-xylene.
6. A process according to claim 2 wherein said aromatic compound is fluorobenzene.
7. A process according to claim 2 wherein the polymerization of the 1-olefin is a particle form polymerization process.
8. A process according to claim 2 wherein said 1-olefin is ethylene.
9. A process for the polymerization of 1-olefins in the presence of a chromium oxide catalyst the improvement which comprises: carrying out said polymerization in the presence of an effective melt index increasing amount of at least one aromatic compound selected from the group consisting essentially of the fluorine, chlorine and bromine monohalogenated derivatives of benzene and mixtures thereof, under such conditions that a polymer is produced having an increased melt index relative to polymers made under similar conditions in the absence of the aromatic compound.
10. A process according to claim 9 wherein said aromatic compound is fluorobenzene.
11. A process according to claim 9 wherein the amount of aromatic compound used is from about 1 to about 500 ppm based on the weight of diluent that is contained in the reactor.
12. A process according to claim 9 wherein the polymerization of the 1-olefin is a particle form polymerization process.
13. A process according to claim 9 wherein said 1-olefin is ethylene.
14. A polymerization process for the polymerization of 1-olefins in the presence of a chromium oxide catalyst and a liquid diluent which comprises the steps of:
(a) reducing said chromium oxide catalyst with a suitable reducing agent,
(b) contacting said reduced catalyst with vapors of at least one aromatic compound selected from the group consisting essentially of: the fluorine, chlorine and bromine monohalogenated derivatives of benzene and mixtures thereof, under such conditions as to add at least one mole of said aromatic compound per mole of chromium present in the catalyst, and
(c) charging said pretreated chromium oxide catalyst to the reactor and then polymerizing said 1-olefin.
15. A process according to claim 14 wherein said aromatic compound is fluorobenzene.
16. A process according to claim 14 wherein said suitable reducing agent of step (a) is carbon monoxide.
17. A process according to claim 14 wherein the polymerization of the 1-olefin is a particle form polymerization process.
18. A process according to claim 14 wherein said 1-olefin is ethylene.
US05/866,900 1978-01-04 1978-01-04 Olefin polymerization Expired - Lifetime US4194073A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US05/866,900 US4194073A (en) 1978-01-04 1978-01-04 Olefin polymerization

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US05/866,900 US4194073A (en) 1978-01-04 1978-01-04 Olefin polymerization

Publications (1)

Publication Number Publication Date
US4194073A true US4194073A (en) 1980-03-18

Family

ID=25348680

Family Applications (1)

Application Number Title Priority Date Filing Date
US05/866,900 Expired - Lifetime US4194073A (en) 1978-01-04 1978-01-04 Olefin polymerization

Country Status (1)

Country Link
US (1) US4194073A (en)

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5064796A (en) * 1991-01-07 1991-11-12 Exxon Chemical Patents Inc. Support adjuvant for improved vanadium polymerization catalyst
EP0870773A1 (en) * 1997-04-10 1998-10-14 BP Chemicals Limited Ethylene polymerization process in the presence of a chromium oxide catalyst
US20050101751A1 (en) * 2002-12-20 2005-05-12 Shaffer Timothy D. Halogenated polymers with new sequence distributions
US20050267269A1 (en) * 2004-05-20 2005-12-01 Hagerty Robert O Polymerization process
US20060079655A1 (en) * 2002-12-20 2006-04-13 Chung David Y Polymers with new sequence distributions
US20060084770A1 (en) * 2002-12-20 2006-04-20 Milner Scott T Polymerization processes
US20060100398A1 (en) * 2002-12-20 2006-05-11 Exxonmobil Chemical Patents Inc. Polymerization processes
WO2006009944A3 (en) * 2004-06-21 2006-06-01 Exxonmobil Chem Patents Inc Polymerization process
US20070197753A1 (en) * 2004-06-21 2007-08-23 Peijun Jiang Polymerization Process
US20070208154A1 (en) * 2004-06-21 2007-09-06 Stavens Kevin B Low Fouling and High Activity Polymerization Process
US20070244279A1 (en) * 2004-06-21 2007-10-18 Exxonmobil Chemical Patents Inc. Polymerization Process
US20080033127A1 (en) * 2005-06-20 2008-02-07 Peijun Jiang Polymerization Process
US20080065360A1 (en) * 2006-09-07 2008-03-13 Univation Technologies, Llc Methods for on-line determination of degree of resin stickiness using a model for depression of melt initiation temperature
US20090118466A1 (en) * 2004-06-21 2009-05-07 Exxonmobil Chemical Patents Inc. Polymer recovery method
US7662892B2 (en) 2004-06-21 2010-02-16 Exxonmobil Chemical Patents Inc. Impact copolymers
US7683140B2 (en) 2004-05-20 2010-03-23 Univation Technologies, Llc Method for determining temperature value indicative of resin stickiness from data generated by polymerization reaction monitoring
US20100144983A1 (en) * 2006-09-07 2010-06-10 Univation Technologies, Llc Methods for determining temperature value indicative of resin stickiness from data generated by polymerization reaction monitoring
US7754830B2 (en) 2004-05-20 2010-07-13 Univation Technologies, Llc Polymerization reaction monitoring with determination of induced condensing agent concentration for preventing discontinuity events
US8399580B2 (en) 2010-08-11 2013-03-19 Chevron Philips Chemical Company Lp Additives to chromium catalyst mix tank
US10005861B2 (en) * 2016-06-09 2018-06-26 Chevron Phillips Chemical Company Lp Methods for increasing polymer production rates with halogenated hydrocarbon compounds

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3846392A (en) * 1971-09-20 1974-11-05 Kanegafuchi Chemical Ind Method of manufacturing cycloolefines
US3891611A (en) * 1972-06-24 1975-06-24 Mitsubishi Chem Ind Process for polymerizing olefins
US3970613A (en) * 1974-03-08 1976-07-20 Bp Chemicals International Limited Polymerization process

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3846392A (en) * 1971-09-20 1974-11-05 Kanegafuchi Chemical Ind Method of manufacturing cycloolefines
US3891611A (en) * 1972-06-24 1975-06-24 Mitsubishi Chem Ind Process for polymerizing olefins
US3970613A (en) * 1974-03-08 1976-07-20 Bp Chemicals International Limited Polymerization process

Cited By (57)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5064796A (en) * 1991-01-07 1991-11-12 Exxon Chemical Patents Inc. Support adjuvant for improved vanadium polymerization catalyst
EP0870773A1 (en) * 1997-04-10 1998-10-14 BP Chemicals Limited Ethylene polymerization process in the presence of a chromium oxide catalyst
FR2761998A1 (en) * 1997-04-10 1998-10-16 Bp Chemicals Snc PROCESS FOR (CO-) POLYMERIZATION OF ETHYLENE IN THE PRESENCE OF A CHROME OXIDE-BASED CATALYST
US20060100398A1 (en) * 2002-12-20 2006-05-11 Exxonmobil Chemical Patents Inc. Polymerization processes
US20060111522A1 (en) * 2002-12-20 2006-05-25 Mcdonald Michael F Polymerization processes
US7723447B2 (en) 2002-12-20 2010-05-25 Exxonmobil Chemical Patents Inc. Polymerization processes
US20060079655A1 (en) * 2002-12-20 2006-04-13 Chung David Y Polymers with new sequence distributions
US20060084770A1 (en) * 2002-12-20 2006-04-20 Milner Scott T Polymerization processes
US20060089467A1 (en) * 2002-12-20 2006-04-27 Exxonmobil Chemical Patents Inc. Polymerization processes
US20060094847A1 (en) * 2002-12-20 2006-05-04 Milner Scott T Polymers substantially free of long chain branching
US7332555B2 (en) 2002-12-20 2008-02-19 Exxonmobil Chemical Patents Inc. Polymers with new sequence distributions
US20060100409A1 (en) * 2002-12-20 2006-05-11 Shaffer Timothy D Polymers with new sequence distributions
US20050107536A1 (en) * 2002-12-20 2005-05-19 Shaffer Timothy D. Polymers with new sequence distributions
US7582715B2 (en) 2002-12-20 2009-09-01 Exxonmobil Chemical Patents Inc. Polymers substantially free of long chain branching
US7491773B2 (en) 2002-12-20 2009-02-17 Exxonmobil Chemical Patents Inc. Halogenated polymers with new sequence distributions
US7425601B2 (en) 2002-12-20 2008-09-16 Exxonmobil Chemical Patents Inc. Polymers with new sequence distributions
US7423100B2 (en) 2002-12-20 2008-09-09 Exxonmobil Chemical Patents Inc. Polymerization processes
US7214750B2 (en) 2002-12-20 2007-05-08 Exxonmobil Chemical Patents Inc. Polymerization processes
US7232872B2 (en) 2002-12-20 2007-06-19 Exxonmobil Chemical Patents Inc. Polymerization processes
US20050101751A1 (en) * 2002-12-20 2005-05-12 Shaffer Timothy D. Halogenated polymers with new sequence distributions
US7332554B2 (en) 2002-12-20 2008-02-19 Exxonmobil Chemical Patents Inc. Polymers with new sequence distributions
US20080045676A1 (en) * 2004-05-20 2008-02-21 Univation Technologies, Llc Polymerization process
WO2005113610A3 (en) * 2004-05-20 2007-04-26 Exxonmobil Chem Patents Inc Polymerization process
US7300987B2 (en) 2004-05-20 2007-11-27 Univation Technologies, Llc Polymerization process
US7858719B2 (en) 2004-05-20 2010-12-28 Exxonmobil Chemical Patents Inc. Polymerization process
US7754830B2 (en) 2004-05-20 2010-07-13 Univation Technologies, Llc Polymerization reaction monitoring with determination of induced condensing agent concentration for preventing discontinuity events
US20050267269A1 (en) * 2004-05-20 2005-12-01 Hagerty Robert O Polymerization process
US7683140B2 (en) 2004-05-20 2010-03-23 Univation Technologies, Llc Method for determining temperature value indicative of resin stickiness from data generated by polymerization reaction monitoring
US7507780B2 (en) 2004-05-20 2009-03-24 Univation Technologies, Llc Polymerization process
US7122607B2 (en) 2004-05-20 2006-10-17 Univation Technologies, Llc Polymerization process
US20080287615A1 (en) * 2004-05-20 2008-11-20 Robert Olds Hagerty Polymerization Process
US20070004878A1 (en) * 2004-05-20 2007-01-04 Univation Technologies, Llc Polymerization process
US20090118466A1 (en) * 2004-06-21 2009-05-07 Exxonmobil Chemical Patents Inc. Polymer recovery method
WO2006009944A3 (en) * 2004-06-21 2006-06-01 Exxonmobil Chem Patents Inc Polymerization process
US7414100B2 (en) 2004-06-21 2008-08-19 Exxonmobil Chemical Patents Inc. Polymerization process
US7491776B2 (en) 2004-06-21 2009-02-17 Exxonmobil Chemical Patents Inc. Polymerization process
US7981984B2 (en) 2004-06-21 2011-07-19 Exxonmobil Chemical Patents Inc. Polymerization process
US20070197753A1 (en) * 2004-06-21 2007-08-23 Peijun Jiang Polymerization Process
US20070244279A1 (en) * 2004-06-21 2007-10-18 Exxonmobil Chemical Patents Inc. Polymerization Process
US7858736B2 (en) 2004-06-21 2010-12-28 Exxonmobil Chemical Patents Inc. Polymer recovery method
US7662892B2 (en) 2004-06-21 2010-02-16 Exxonmobil Chemical Patents Inc. Impact copolymers
US20070208154A1 (en) * 2004-06-21 2007-09-06 Stavens Kevin B Low Fouling and High Activity Polymerization Process
WO2006009949A3 (en) * 2004-06-21 2007-09-07 Exxonmobil Chem Patents Inc Low fouling and high activity polymerization process
US20070293638A1 (en) * 2004-06-21 2007-12-20 Exxonmobil Chemical Patents Inc. Polymerization Process
US7423103B2 (en) 2004-06-21 2008-09-09 Exxonmobil Chemical Patents Inc. Low fouling and high activity polymerization process
US20080033127A1 (en) * 2005-06-20 2008-02-07 Peijun Jiang Polymerization Process
US7799882B2 (en) 2005-06-20 2010-09-21 Exxonmobil Chemical Patents Inc. Polymerization process
US7774178B2 (en) 2006-09-07 2010-08-10 Univation Technologies, Llc Methods for on-line determination of degree of resin stickiness using a model for depression of melt initiation temperature
US20100144983A1 (en) * 2006-09-07 2010-06-10 Univation Technologies, Llc Methods for determining temperature value indicative of resin stickiness from data generated by polymerization reaction monitoring
US20080065360A1 (en) * 2006-09-07 2008-03-13 Univation Technologies, Llc Methods for on-line determination of degree of resin stickiness using a model for depression of melt initiation temperature
US8273834B2 (en) 2006-09-07 2012-09-25 Univation Technologies, Llc Methods for determining temperature value indicative of resin stickiness from data generated by polymerization reaction monitoring
US8399580B2 (en) 2010-08-11 2013-03-19 Chevron Philips Chemical Company Lp Additives to chromium catalyst mix tank
US8759459B2 (en) 2010-08-11 2014-06-24 Chevron Phillips Chemical Company Lp Additives to chromium catalyst mix tank
US10005861B2 (en) * 2016-06-09 2018-06-26 Chevron Phillips Chemical Company Lp Methods for increasing polymer production rates with halogenated hydrocarbon compounds
US10167353B2 (en) 2016-06-09 2019-01-01 Chevron Phillips Chemical Company Lp Methods for increasing polymer production rates with halogenated hydrocarbon compounds
CN109153740A (en) * 2016-06-09 2019-01-04 切弗朗菲利浦化学公司 Process for increasing polymer production rates using halogenated hydrocarbon compounds
CN109153740B (en) * 2016-06-09 2021-04-02 切弗朗菲利浦化学公司 Process for increasing polymer production rates using halogenated hydrocarbon compounds

Similar Documents

Publication Publication Date Title
US4194073A (en) Olefin polymerization
US3970613A (en) Polymerization process
US3362946A (en) Method of treating supported chromium oxide catalyst and polymerization therewith
US3976632A (en) Reactivation of organochromium olefin polymerization catalyst in presence of oxygen
US4041224A (en) Catalyst, method and polymerization processes
US4101445A (en) Preparation of modified and activated chromocene catalysts for ethylene polymerization
US3622521A (en) Olefin polymerization with chromium and titanium-containing compounds
US4173548A (en) Ethylene polymerization catalyst and method
US4517345A (en) Polymerization process
CA1074285A (en) Polymerisation catalyst
US6646069B2 (en) Ethylene polymers and method for producing the same
US4559394A (en) Olefin polymerization using activated chromium catalyst treated with tertiary alcohol
US3130188A (en) Catalyst and process for producing olefin polymers
US4130505A (en) Two stage activation of fluorided chromium-containing catalyst
US4246139A (en) Silica production
US4039632A (en) Preparation of block copolymers
US4188471A (en) Organochromium on titanium-impregnated base as olefin polymerization catalyst
JPH06184233A (en) Polymerization of ethylene
US2846425A (en) Stabilized catalyst and improved polymerization process
US4369295A (en) Impregnated second valence chromium compound in supported catalyst
US4025707A (en) Mixed hydrocarbyloxide treated catalyst activated at different temperatures
KR101667830B1 (en) Methods of preparing a polymerization catalyst
US4184979A (en) Catalyst and process of preparing the catalyst
US3378536A (en) Polymerization process using a catalyst comprising a supported diarene metal and supported chromium oxide
US4382020A (en) Process for the preparation of an olefin polymerization catalyst